"After nearly 16 years, I've decided it's time for me to step away from day-to-day operations," Glaser said in the statement.
Real said Glaser will remain at the company as chairman and appointed Robert Kimball as president and acting chief executive officer. The announcement comes a day after Real announced that John Giamatteo, the company's chief operating officer, had resigned.
Glaser jumped from Microsoft after spending 10 years working for CEO Bill Gates to form RealNetworks. He built the company's proprietary software formats, RealAudio and RealVideo, into powerhouses. In the early days of the Web, Real was nearly synonymous with online video and audio.
But Real was eclipsed by MP3 and other formats in music and the company appeared to sit on its heels when the video boom erupted on the Web in 2006. When Chad Hurley and Steve Chen launched YouTube, it touched off huge interest in video. Real couldn't seem to capitalize and the company's influence has been on the wane every since.
Throughout Glaser's technology career, he built a reputation for never backing down from a fight, even when it may have made sense.
In 2005, Real
In 2008, Real launched a legal campaign against the major film studios when it became apparent
Last year, U.S. District Judge Marilyn Patel
Whether Real plans to pursue the costly and legal campaign is unclear.
By Greg Sandoval